Haha! Sorry i cant be of any help, i have no experience in dealing with alligators. But i have to say i love the picture og the gator "ringing" the door bell. Now if it was my house that it was trying to intrude into i would be freaking out. Props to all you who live down in florida, i couldnt stand to live with them.
Actually I'd think that an alligator would be fairly easy to fence out (and surely there must be BYCers who don't need to photoshop to get a pic like that)... they are pretty conductive and can't climb/jump/burrow, so a couple of strands of well-charged electric fence should do the job?
Saltwater crocodiles btw are NATIVE to Florida, just real rare at least in the past hundred years or so.